I said the rings run hotter just to clarify...and they do, which IS the reason for the larger gap because when they expand, and if you used the standard gap, the rings would butt and then it would seize the piston in the hole AND then the piston would explode due to its brittleness.
Again, you'll save roughly 800kg (roughly 2 lbs) of rotating weight by using the lighter pistons. The difference is modest when you think of the weight of the whole thing. There's at least 120 lbs of metal flying around in there just in the bottom end+flywheel+balancer.
Speed Pro says:
"Piston weight has recently become a very high profile topic in the performance media. Realistically, a reduction in piston weight has only a modest impact on horsepower or vehicle accelleration. The true value of reduced weight lies in the potential for higher RPM as a result of the reduced loads on components such as connecting rods and bearings. Optimisting the engine combination for these higher RPM levels will certainly carry the potential for more power."
And talking about Hypereutectic pistons: "...This quiet operation, along with a lower cost are the primary advantages over a comparable forged piston."
So lets recap:
Hypereutectic Pistons:
Pro's:
Lighter weight
Quieter when cold
Cheaper (not by much)
Cons:
Brittle (failure mode is exploding)
Not as durable as forged
Special ring gap
Forged:
Pros:
Most Durable
Ductility
Standard gaps
Cons:
Price (again, not much)
heavier
might rattle a bit when cold.
Bottom line is: The Hypereutectic pistons don't have a different compression height than the forged...so I still have the same original problem. So, in my original question, it does not help. I'm not trying to turn this thing 9 grand or anything. I would, however, like to run this engine a bit on the lean side in cruise, and while doing so, I may detonate it during the tuning process as I also run a LOT of timing. Forged pistons hold up better in these conditions. I'm also not worried about the weights cause of stress on the crank and rods. These have been around for a while and they're not known for flying apart. I have NEVER read anything about these particular pistons that were bad other than the weight. 440 pistons are even heavier yet. I could really care less about the extra rpm I could have or the incrementally small hp gain I would get. I'm also not worried about high RPM...actually I'd like to reach my HP goal at the lowest RPM possible...and achieve a large area under the curve (good torque).
Also, who knows, down the road I may want a turbo...
And furthermore...if I bought exactly the same parts in that kit but used the KB's instead of the L2316F's, it would cost $577.13 instead of 632.99...a whole $55.84. A price I am willing to pay. So yes, the hypers may be fine, plain cast pistons might be fine too...I'll leave that for you guys to find out....and I'll stick with the forged.